Valve



March 15, 1938. w. R. JOHNSON VALVE 5 Sheets-Sheet l Filed Oct. 12, 1935 INVENTOR. WWE/Qfi/f/VJO/V M Q, 'f ATTORNEY,

March 15, 1938. w R JOHNSON 2,111,322

' VALVE Filed Oct. 12, 1935 3 Shae'cs-SIu-zeiw I I ATTORNEY March 15, 1938. w R JOHNSCN 2,111,322

' Y VALVE Filed Oct. 12, 1935 3 Sheets-Sheet 5 74 Fla. 6

ATTORNEY,

Patented Mar. is, 1938 lTED STATES poration oi Indiana Application ottom- 12, net, Serial No. titer i115 Wims.

This invention relates to a valve and particularly to a valve especially useful in controlling power brakes. Two types of valves are shown illustrating my invention and also several hook ups showing various uses of the valve.

One of the objects of the invention is the provision of a brake valve which is quicker in action than previously used valves. It is also more positive and is less subject to diiilculties on account of dirt and so forth.

Further objects and features of the invention will be apparent after a reading of the subjoined specification and claims and after a consideration of the accompanying drawings in which:

Figure 1 is a largely diagrammatic plan view showing a brake arrangement-for a tractor and a trailer in which the tractor brakes are applied mechanically and in which the trailer brakes are applied by vacuum power which is controlled by the mechanical actuation of the tractor brakes;

Figure 2 is a view similar to Figure N1 showing an arrangement in which the power application of the trailer brakes is entirely independent of the mechanical actuation of the tractor brakes;

Figure 3 is a view similar to Figures 1 and 2 showing an arrangementin which both the trailer and the tractor brakes are applied by vacuum power and in which the two systems are dependent;

Figure 4 is a view similar to Figures 1, 2 and 3 showing an arrangement in which both the tractor and the trailer brakes are appl ed ploy vacuum power but in which the control of the trailer brakes is separate and independent of the control of the tractor brakes;

Figure 5 is a detailed view in section of a relay valve embodying my invention being one of the valves used in the hook ups shown in Figures 1-4; and

Figure 6 is a detailed view in section of hand control valve embodying my invention being the hand-controlled valve shown in Figures 2 and 4.

Referring in detail to the drawings there is shown in Figure l a tractor III, a trailer I2, each provided with roadwheels ll equipped with brakes. The brakes of both vehicles are arranged to be operated by tension connections IE each of which is connected to one of the cross i. aria-5i) a power cylinder 2% secured to the frame of the trailer and arranged to operate the cross shaft 2w by means of a piston rod 3% connected at one end to the piston of the cylinder 2% and at the other end to an arm on the cross shaft 2t.

Power cylinder 28 is. operated through differentials in pressure between the pressure existing in the atmosphere and that existing in the manifold. It is controlled by the pedal valve 2d and the relay valve 32. The relay valve 32 is shown in detail in Figure 5 and will be subsequently described. Suitable conduits connect the intake manifold 34 with the forward end of the power cylinder 28 and constitutes a vacuum line designated 36. This vacuum line 36 is connected by a branch conduit 38 with control valve 2t and control valve 24 is connected by a conduit M with relay valve 32. The conduit Mi may be designated as the air line for convenience, because at other times it is filled with air though at other times it is evacuated to the same degree of vacuum as the intake manifold Preferably a check valve H2 is inserted in the line it adjacent to the intake manifold 34. I

The relay valve 32 is shown more in detail in Figure 5. It comprises the main casing M formed at one end (called the forward end for convenience) with a threaded opening it which is connected to the rearward end of the cylinder 28. The casing 4 1 is also formed with an opening t'l into which a plug it is inserted and secured, plug t having a threaded-opening til into which the conduit 3'! is secured. The inner end of the plug is formed with a valve seat 52 onto which a poppet valve 54 is arranged at times to seat. The casing 44 is alsoformed with an opening 56, formed with a valve seat onto which a popp t valve 58 normally seats. The valves 5t and 5d are provided with stems 60 and t2 respectively. The casing 44 is formed with an annular inward extension aligned with the opening 45 the extension being provided with aligned openings through which the stems 60 and B2 are adapted" to slide. A forward cover 66 is provided for the casing 44 and this .cover 66 is sealed to the casing by means of packings such as 68, I0 and 12. I

It cooperates with the casing 44 to form an air inlet chamber 14 which communicates with the atmosphere through the air strainer IS. The air chamber 14 is arranged at times to communicate with the interior of the casing 44 through opening 56 but normally the poppet valve 58 closes this opening so that atmosphere is out off from the interior of the casing 44. Normally the p ppet valve 54 is held of! its seat so that the connection from the intake manifold 34 through the vacuum line 36 and the conduit 31 maintains the interior of the casing 44. under equal pressure with that of the intake manifold, that is to say under a substantial amount of vacuum.

Means are provided for maintaining the poppet valves 54 and 58 in the normal position shown in Figure 5 and for at times moving said valve from said position. The rearward end of the the casing 44 is closed by a diaphragm I8 and a cap 80, the former being clamped between the cap and the casing and the latter being held on link 86 with a triangular plate 88 by means of a. pin 90. The triangular plate 88 is provided with pins 92 and 94 which extend through slots in the stems 60 and 62. The plate 88 is thus in effect a bell crank lever connected to the stems 60 and 62 and the diaphragm I8. The stem 82 .is provided with a! spring 96 interposed between a shoulder 98 and a portion of the annular extension 64. The spring 96 tends to hold the valve 58 upon its seat. At the same time it causes the pin 92 to form a resilient fulcrum for the plate 88 so that the resiliency of the diaphragm I8 in its outward positionas shown normally holds the valve 54 off of its seat. The chamber formed by the outer side of the diaphragm I8 is designated as I00 and the chamber formed in the casing 44 inward of the diaphragm I8 is designated as I02. Variations in pressure between these chambers control the diaphragm and movement of diaphragm I8 inward causes a resulting movement of the .pivot point 80 and tends to lift the stem 62 and to lower the pivotal connection 94 thus closing the valve 54 and subsequently opening valve 56. Inasmuch as the chamber 14 is connected to the atmosphere this allows atmospheric pressure to enter the chamber I02 and through the opening 46 to enter the rearward end of the power cylinder.

Inasmuch as the diaphragm I8 is balanced between the pressure existing in I00 and I02 the introduction of air in I02 tends to reverse the valves again and the exact amount of air intro- -duoed into I02 is controlled by the amount of air the'operator introduces into the chamber I00.

The reason for the straddle springs 26 is as follows: On some types of vacuum brake power installation (particularly tractor-trailer combinations) where the trailer only is equipped with power brakes, it is essential to have some means whereby the manually operated brakes on the tractor may be synchronized with the power brakes on the trailer. This type of installation usually consists of a brake valve mounted on the foot brake pedal rod controlling the power cylinder of the trailer. To overcome the possibility of the trailer brake taking hold too quickly and thereby doing most of the braking before the manually operated tractor brakes are allowed to do their share, it is necessary to install a set of straddle springs as shown. By adjusting the tension of the spring it is possible to synchronize the pressure required to open the brake valve to that required to apply the tractor brakes. If the trailer brakes operate too much ahead of those on the tractor, the tension on the. springs may be increased by means of an adjusting nut. Increasing the tensionoi' springs allows the tractor brakes to operate earlier, decreasing the spring tension allows the trailer brakes to operate ahead conduit 38 and the conduit 40 and thus cuts off the vacuum which is normally in the line 40 and introduces atmospheric air which thus enters the chamber I00. This movesthe diaphragm I8 forward thus closing the valve 54 and opening the valve 58. The closing of the valve 54 shuts off the vacuum which is, normally present in the chamber I02 through its connections through the opening 50, the conduit 31 and the vacuum line 36 and allows atmospheric air to flow in from the chamber I4 into the chamber I02 and thus end causes movement of the power cylinder which pulls on the connection 30 and thus applies the brakes on the trailer wheels. Similarly release of the brakes on the tractor wheels relieves the tension on the connection 22 and thus opens the valve 24 so that the manifold is again connected through the conduit 40 with the chamber I00 and the pressures in the chamber I00 and I02 becoming equalized, the spring 06 opens the valve 54 and closes the valve 58. Thereupon the chamber I 02 is connected to the manifold through the conduit 31 and the vacuum line 36 and thus the rearward end of the power cylinder 28 is evacuated. The opposite side oi the powerpiston then having equal pressure the return springs relieve the brakes on trailer wheels.

In the showing of Figure 2 like parts have been designated by the same numerals with the addition of 200 and a repetition of the description is believed to be unnecessary. However the cross shaft 2 I8 is connected directly to the pedal through a link 222 in which there is interposed no valve corresponding to the valve 24. In place of the valve 24 there is provided between the conduit 238 and the conduit 240 a hand control 2I3 which is shown more in detail in Figure 6.

. The hand controlled valve 2I3 is to a large extent the same as the relay valve 32 and like parts are designated by'the'same numerals, repetition of the description being believed unnecessary. Instead of the cap 80 there is provided a cover I I5 the outer end of which is provided with a handle I" for controlling the valve. Connected to this handle I" by means of a nut H3 is a cam I2I arranged to act upon a disc I23 to move the disc I23 inward thus compressing a spring I25 interposed between the diaphragm I8 and the disc I23. A passage formed in the plug 48, the casing 44, the diaphragm I8, and the cover 5 provides a commimication between the inlet passage 50 and the chamber between the cover H5 and the diaphragm. Thus the diaphragm I8 trolled by the position of the handle Ill. Similarly pressure in the chamber I02 of the hand control valve is transmitted from the opening 46 through the conduit 240 to the relay valve 232 and controls the pressure in the chamber lllll thereof. Inasmuch as the diaphragm it of the relay valve is balanced between the pressure in the chamber ltli and that in the chamber M2, the pressure in the chamber N2 of the relay valve is also accurately controlledso that the pressure applying the brake through the vacuum cylinder 228 is accurately handle ill.

Similarly in Figure 3 like parts are designated by the same reference numerals with the addition controlled by the hand control of tilt and parts previously described will not again be described. As may be seen the valve 326 controls not only the relay valve 33d, but also through a branch conduit Ml controls the power cylinder 321 which has its piston connected through the link iii to the cross shaft did. The vacuum line 336 is connected-by a branch conduit 335 with the forward end of the power cylinder 321i. are applied by vacuum power, though in case of a failure of the vacuum power the tractor brake can, be applied manually through the link 322.

also in the arrangement shown in Figure 4 the same parts as are designated by the same numerals with the addition of Mid. Therein the manifold 434 is connected by a conduit 33601) with a tractor vacuum tank 1360)) which is connected through a vacuum line dllhc) with a trailer vacuum tank @3601). A conduit ddllia) is connected by a branch conduit dldlb) with a pedal controlled valve 624 and is also connected with a hand control valve M3. The pedal controlled valve lt l is connected by a conduit time) with the rearward end of power cylinder til and the forward end of said cylinder 42l is connected a by a branch conduit 435 with conduit Md and with vacuum tank 43ml). The hand control valve did is connected by a conduit Mum) with relay valve iii. The relay valve is connected to the rearward end of power cylinders time) and 42t(bl whichare each connected with a separate bralre for each of the rear wheels of the trailer. The trailer vacuum tank ttfid) is connected bi! branch conduits Mite) and tdtif) with the forward ends of power cylinders Mimi) and ditw) respectively.

The operation of the arrangements shown in Figures 2, 3 and d is similar to that described above in connection with Figure l and it is believed that a separate description of the operation of these arrangements need not be made.

It is tobe understood that the above described embodiments of my invention are for the purpose of illustration only and various changes may be made therein without departing from the spirit and scope of the invention.-

I claim: a 1. In a control valve for automotive brakes, a casing having a pair of valve'seats arranged on opposite sides of the casing, a pair of poppet valves for coaction with said seats, oppositelydirected stems on the valves extending across the casing in parallel relation witheach other, a. floating lever connected to the stems and means for operating said lever for first closing one valve and then opening the other.

. 2. The structure claimed in. claimv 1 further characterized in that the means for controlling Thus both the tractor and the trailer brakes said lever includes a diaphragm and that when. one valve is opened it admits air under a relatively high pressure while when the other valve is opened it connects the casing with a source of relatively low air pressure.

3. The structure described in claim 1 further characterized in that the means for controlling said lever includes a hand control and that when one valve is opened it admits air under a. relatively high pressure while when the other valve is opened it connects the casing with a source of relatively low air pressure.

4. The structure described in claim 1 further characterized in that the means for controlling said lever includes a hand control element and a diaphragm and that when one valve is opened it admits air under a relatively high pressure "while when the other valve is opened it connects the casing with a source of relatively low air pressure.

5. The structure described in claim 1 further characterized in that the means for controlling said lever includes a diaphragm, a, hand control element, and a spring interposed between said diaphragm and said hand control element and that when one valve is opened it admits air under a relatively high pressure while when the other valve is opened it connects the casing with a source of relatively low air pressure.

6. The structure described in claim 1 further characterized'in that the means for controlling said lever includes a diaphragm exposed to the existing pressure in said casing, and means for conducting air under pressure to the opposite side of said diaphragm.

7. The structure described in cl 1 furtlier characterized in that the 'means for controlling said lever includes a diaphragm exposed to the emsting pressure in said casing, and also exposed to a varying air pressure under the control of the operator.

t. The structure described in claim 11 further characterized in that the casing .is provided with an outlet opening having an inwardly extending annular flange formed with two pairs of aligned openings through which said stems mtend.

9. A valve comprising a casing having a pair of valve seats, a pair of poppet valves for coaction with said seats, a pair of stems each formed with a slot and each connected to one of said valves, a floating lever comprising a triangular plate provided with three pins, one adjacent eachof the corners thereof, two of said pins extending pins, one adjacent each of v the corners thereof,

two of said pins extending through said slots in the valve stems, and means comprising a link pivotally connected to the other pin for operating said lever.

11. A valve comprising a casing having a pair of valve seats, a pair o p ppet valves for coaotlon with said seats each provided with a stem extending inwardly from said valve so as to be arranged slot, a floating lever comprising a triangular plate parallel to each other and each formed with a provided with three pins, one adjacent each of 4 the corners thereof, two of said pins extending through said slots in the valve stems, and means comprising a link pivotally connected to the other pin for operating said lever.

' 12. In a control valve for automotive brakes, a casing having a pair of valve seats arranged on opposite sides of the casing, apair or poppet valves for coaction with said seats, oppositelydirected stems on the valves extending across the casing in parallel relation with each other, a floating lever connected to the stems and means for operating said lever for first closing one valve and then opening the other, the stems of the valves being positioned so closely that the valves are in substantialoverlapping position.

13. In a control valve for automotive braking systems employing high and low pressures, a casing, a valve seat on the outside of said casing surrounding a port having a connection with a source of the high pressure, a valve on said seat opening outwardly toward said high pressure, a valve seat on the inside of said casing surrounding a part communicating with a source 01' said low pressure, a valve on said seat closing toward said low pressure, a floating lever connected to the valves, and means for operating the lever to first close one valve and then open the other.

. 14. In a control valve for automotive braking systems employing high and low pressures, a casmg. a diaphragm dividing the casing mm two parts, a pair of valve seats in one part of said casing surrounding ports, one of which communicates with a source of the high pressure and one of which communicates with a source of the low pressure, valves in said ports, a floating lever connected to said valves, means connecting the floating lever to the diaphragm, a spring in the other part oi said casing bearing on said diaphragm, and manual means for varying the pressure of said spring, said other part of the casing being sealed against air leakage and having a passage extending to and communicating with the source of low pressure.

15. In a relay valve for automotive brakes, a casing, a diaphragm dividing the casing into two chambers, one of said chambers being formed with a. port and having a controlled pressure communicating therewith through said port and the other chamber being formed with three ports one of which transmits a controlled pressure to the brake,.and the other two'oi which are connected respectively to sources of high and low pressure, poppet valves in the last-named two ports, a floating lever connected to the poppet valves, and operable to first close one and open the other, and means connecting the diaphragm to the floating lever to operate the same.'

WAYNE R. JOHNSON. 

